Radio communication method and radio communication terminal

ABSTRACT

A first radio communication processor  110  for making a first bidirectional radio communication with a predetermined station, a second radio communication processor  120  for making a second bidirectional radio communication with an adjacent reader/writer in non-contact manner, and a controller  117  for temporarily stopping output of transmission data in the first radio communication processor when the start of the second radio communication with the reader/writer is detected, are provided.

BACKGROUND OF THE INVENTION

The present invention relates to a radio communication method and aradio communication unit suitably applied to a mobile phone unit,particularly to the art in which a function of making communication fora non-contact IC card is incorporated into the unit.

It has been heretofore practiced to utilize the non-contact IC card formaking various data communication in a short distance. For example, thenon-contact IC card is used for a railroad ticket and the like.Specifically, a reader/writer of the non-contact IC card is installed ata wicket; the non-contact IC card is brought close to the reader/writerwhen passing the wicket; and data stored in the non-contact IC card isread to perform authentication processing and the like.

There are two types of non-contact IC card: a type with a built-inbattery and another type without a built-in battery; however, in view ofeasiness to handle, an operational life and so on, recently the typewithout a built-in battery has widely been used. In the case where thenon-contact IC card without a battery is used, an electric power wave issupplied from the reader/writer side; an antenna on the side of IC cardreceives the electric power wave to store power in a capacitor in the ICcard; and the stored power is utilized for driving the IC card. Thus,the IC card must be brought very close to the reader/writer.

In addition to the above-described railroad ticket, the non-contact ICcard is now being applied to an electronic money card, a personalidentification card such as an employee identification card and thelike. In NIKKEI ELECTRONICS, No. 798, pages 55 to 60 (published byNikkei Business Publications Inc. on Jun. 18, 2001), there is adescription about this non-contact IC card. Note that although thenon-contact IC card need not necessarily take a card shape, in thisspecification a non-contact structure for making a short-distancecommunication of this kind will be referred to as the non-contact ICcard or IC card.

Hereupon, if the non-contact IC card is integrated with portableelectronic equipment carried by the user or if the IC card can beinstalled in the portable electronic equipment, then it will beunnecessary to carry the relevant electronic equipment separately fromthe IC card and it is convenient for the user. A mobile phone unit isone of the portable electronic equipment on which such integration isassumed.

However, since the mobile phone unit is equipment that transmits andreceives an electric wave, when it is assumed that the mobile phone unitis integrated with the non-contact IC card, a radio signal exchangedbetween the IC card and reader/writer will very likely make anundesirable effect on a signal used in radio telephone communicationbetween the mobile phone unit and a base station or the like.

Conventionally, a frequency bandwidth of the radio signal used in themobile phone system (from several hundred MHz to several GHz, forexample) is different from a frequency bandwidth of the radio signalexchanged between the non-contact IC card and reader/writer (severaltens of MHz, for example). However, harmonics of the radio signaltransmitted between the non-contact IC card and reader/writer will mostlikely be a jamming wave against the radio signal used in the mobilephone system.

Therefore, when a function of IC card for non-contact communication ofthis kind is incorporated in the mobile phone unit, such measures as:adding an anti-interference exclusive circuit to the unit in accordancewith a radio communication frequency and a controller-operating clockfrequency as the IC card as well as a radio communication frequency anda controller-operating clock frequency as the mobile phone; shieldinginside the equipment a circuit portion functioning as the mobile phoneunit and a circuit portion functioning as the non-contact IC card frombeing interfered with each other; and the like are required, which posesa problem to make the structure of equipment complicated.

The present invention has been made in view of the above problems andaims to prevent without difficulty the mutual interference when thenon-contact IC card function is incorporated into the mobile phone unit.

SUMMARY OF THE INVENTION

A first aspect of the present invention is a radio communication methodin which a function of making a first bidirectional radio communicationwith a predetermined station and a function of making a secondbidirectional radio communication with an adjacent reader/writer areperformed, wherein

when the start of the second radio communication with the reader/writeris detected, output of transmission data in the first radiocommunication with the predetermined station is temporarily stopped.

According to the above configuration, even if a signal generated by thecommunication with the reader/writer may jam another signal transmittedto the predetermined station, because output of transmission data to thepredetermined station is stopped temporarily, an error, etc. due to thejamming wave can be prevented from being caused in data arriving at thepredetermined station; so that when the non-contact IC card function isincorporated into one mobile phone unit, prevention of the interferencecan be realized efficiently with simplified configuration andprocessing, without providing an exclusive circuit or a shieldmechanism.

A second aspect of the present invention is the radio communicationmethod according to the first aspect of the present invention, in whichthe above temporary stop is the processing to stop inputtingtransmission data into a buffer that temporarily stores the transmissiondata.

According to the above configuration, only output of the transmissiondata can be stopped temporarily without difficulty.

A third aspect of the present invention is the radio communicationmethod according to the first aspect of the present invention, in whichthe temporary stop is the processing to stop inputting the transmissiondata into a buffer that stores the transmission data temporarily, andeven if no data is stored in the buffer, transmission of packets by thefirst communication is continued.

According to the above configuration, the connection of the radiocommunication with the predetermined station is maintained and theprocessing when the output of transmission data is resumed can besimplified.

A fourth aspect of the present invention is the radio communicationmethod according to the first aspect of the present invention, in whichthe temporary stop is the processing to stop inputting the transmissiondata into a buffer that stores the transmission data temporarily, andeven if no data is stored in the buffer, transmission of packets by thefirst communication is continued, where the packets transmitted when nodata is stored are transmitted at the lowest transmission rate.

According to the above configuration, the efficiency of using a radiotransmission line during the temporary stop of outputting data can beimproved.

A fifth aspect of the present invention is the radio communicationmethod according to the first aspect of the present invention, in whichwhen completion of the second radio communication is detected, theprocessing of temporarily stopping transmission data is released.

According to the above configuration, communication of data transmissionwith the predetermined station can be resumed immediately.

A sixth aspect of the present invention is the radio communicationmethod according to the first aspect of the present invention, in whichthe second radio communication operates under power obtained by anelectric power wave supplied from the reader/writer.

According to the above configuration, the detection, for example, of theelectric power wave from the reader/writer can be judged to be the startof radio communication with the reader/writer, so that the start ofradio communication can easily be judged.

A seventh aspect of the present invention is a radio communication unitincluding: a first radio communication processor for performing a firstbidirectional radio communication with a predetermined station,

a second radio communication processor for performing a secondbidirectional radio communication with an adjacent reader/writer, and

a controller for temporarily stopping output of transmission data in thefirst radio communication processor, when the start of the second radiocommunication with the reader/writer is detected.

According to the above configuration, even if a signal generated by thecommunication with the reader/writer may jam another signal transmittedto the predetermined station, because output of transmission data to thepredetermined station is temporarily stopped, an error, etc. due to thejamming wave can be prevented from being caused in data arriving at thepredetermined station; so that when the non-contact IC card function isincorporated into one mobile phone unit, prevention of the interferencecan be realized efficiently with simplified configuration andprocessing, without providing an exclusive circuit or a shieldmechanism.

An eighth aspect of the present invention is the radio communicationunit according to the seventh aspect of the present invention, in whichthe temporary stop under the control of the controller is the processingto stop inputting of transmission data into a buffer that is providedwith the first radio communication processor and stores transmissiondata temporarily.

According to the above configuration, only output of the transmissiondata can be stopped temporarily without difficulty.

A ninth aspect of the present invention is the radio communication unitaccording to the seventh aspect of the present invention, in which thetemporary stop under the control of the controller is the processing tostop inputting transmission data into a buffer that is provided with thefirst radio communication processor and stores the transmission datatemporarily, and even if no data is stored in the buffer, transmissionof packets by the first communication is continued.

According to the above configuration, the connection of the radiocommunication with the predetermined station is maintained and theprocessing when the output of transmission data is resumed can besimplified.

A tenth aspect of the present invention is the radio communication unitaccording to the seventh aspect of the present invention, in which thetemporary stop under the control of the controller is the processing tostop inputting transmission data into a buffer that is provided with thefirst radio communication processor and stores the transmission datatemporarily, and even if no data is stored in the buffer, the control tocontinue transmission of packets by the first communication isperformed, where the packets transmitted when no data is stored aretransmitted at the lowest transmission rate.

According to the above configuration, the efficiency of using a radiotransmission line during the temporary stop of outputting data can beimproved.

An eleventh aspect of the present invention is the radio communicationunit according to the seventh aspect of the present invention, in whichwhen the completion of radio communication in the second radiocommunication processor is detected, the controller releases theprocessing of temporarily stopping transmission data in the first radiocommunication processor.

According to the above configuration, communication of data transmissionwith the predetermined station can be resumed immediately.

A twelfth aspect of the present invention is the radio communicationunit according to the seventh aspect of the present invention, in whichthe second radio communication processor operates under power obtainedby receiving an electric power wave supplied from the reader/writer.

According to the above configuration, the detection, for example, of theelectric power wave from the reader/writer can be judged to be the startof radio communication with the reader/writer, so that the start ofradio communication can easily be judged.

BRIEF DESCRIPTION OF DRAWINGS

FIG. 1 is a block diagram showing an example of a configuration of amobile phone unit according to an embodiment of the present invention;

FIG. 2 is a block diagram showing an example of a configuration forprocessing transmission data according to an embodiment of the presentinvention;

FIG. 3 is a block diagram showing an example of a structure ofcommunication layers according to an embodiment of the presentinvention;

FIG. 4 is a flowchart showing an example of processing of starting ICcard communication according to an embodiment of the present invention;

FIG. 5 is a flowchart showing an example of processing of ending IC cardcommunication according to an embodiment of the present invention;

FIG. 6 is a flowchart showing an example of processing of receivingtransmission packets in a layer 2 according to an embodiment of thepresent invention; and

FIG. 7 is a flowchart showing an example of processing of transmittingthe transmission packets in the layer 2 according to an embodiment ofthe present invention.

DETAILED DESCRIPTION OF THE PRESENTLY PREFERRED EMBODIMENTS

Hereinafter, an embodiment of the present invention will be describedwith reference to the accompanying drawings.

In this embodiment, the non-contact IC card function is incorporatedinto a mobile phone unit that performs bidirectional radio communicationwith a predetermined station (base station) prepared for the mobilephone. Specifically, as is shown in FIG. 1, a mobile phone unit 100 ofthis embodiment includes a mobile phone part 110 and a non-contact ICcard function part 120. The mobile phone part 110 is connected to thenon-contact IC card function part 120 through an interface 130 forcommunication between the mobile phone and IC card, by which datatransfer can be performed mutually. Although the non-contact IC cardfunction part 120 may be integrally provided with the mobile phone unit100, the similar structure can be made by, for example, providing a cardslot in the unit 100 and installing an IC card functioning as thenon-contact IC card function part 120 in the card slot.

The mobile phone part 110 performs bidirectional radio communicationwith the base station 140 for mobile phones and the like. Specifically,the part 110 includes an antenna 111 for making the radio communicationwith the base station 140; the antenna 111 is connected to a modulator113 and a demodulator 114 through an antenna-sharing device 112; asignal modulated by the modulator 113 is transmitted by radio from theantenna 111; and a signal received through the antenna 111 isdemodulated by the demodulator 114. With respect to the modulationprocessing in the modulator 113 and the demodulation processing in thedemodulator 114, such processing as determined in the radio phone systemto which this mobile phone unit is applied is performed. Specifically,the modulation and demodulation are performed based on the processingmethod determined by the applied radio phone system, such as a CDMA(Code Division Multiple Access) method and a TDMA (Time DivisionMultiple Access) method. In this embodiment a telephone unit accordingto a W-CDMA (Wideband-CDMA) system, that is one of radio telephonesystems to which CDMA method is applied, is employed.

A transmission signal supplied to the modulator 113 is generated in acontroller 115. A received signal demodulated by the demodulator 114 isalso supplied to the controller 115. The controller 115 includes acentral processing unit (CPU) 117 as a control means for controlling theoperation of the mobile phone unit, and controls data transfer betweenan input/output device 116 connected to the controller 115 and themodulator 113 and demodulator 114.

When the mobile phone unit 100 is a unit for making a voicecommunication for example, the input/output device 116 has a microphoneand speaker. When the mobile phone unit 100 is a unit to handle variousdata, a circuit for performing input and output of data is included.When the input/output device 116 has the microphone and speaker, audiodata picked up and output by the microphone is supplied to thecontroller 115; control data is added to the audio data under thecontrol of CPU 117 to form a packetized transmission signal; and thetransmission signal is supplied to the modulator 113. Further, audiodata, control data, and the like are extracted in the controller 115from the packetized received signal demodulated by the demodulator 114;and the audio data is supplied to the speaker included in theinput/output device 116 to be output and the control data is supplied tothe CPU 117.

Transmission data supplied from the input/output device 116 istemporarily stored in a transmission buffer 119 provided in thecontroller 115. The controller 115 uses the data stored in thetransmission buffer 119 to generate packets for transmission which issupplied to the modulator 113. The controller 115 further includes anexternal interface 118 for making data transfer with the non-contact ICcard function part 120.

FIG. 2 shows a configuration for adding the control data to data outputfrom the transmission buffer 119. Data supplied from the precedingcircuit (input/output device 116) to an input terminal 119 a of thetransmission buffer 119 is stored in a memory in the transmission buffer119. The data stored in transmission buffer 119 is supplied to aquadrature modulator 162 through a multiplier 161 and is superimposed onthe control data in the quadrature modulator 162. The control datasupplied to an input terminal 163 is supplied to the quadraturemodulator 162 through multipliers 164 and 165.

The transmission data output from the transmission buffer 119 is outputas a signal of a user-data transmission channel (Dedicated Physical DataChannel: DPDCH) and is multiplied in the multiplier 161 by a gaincoefficient βd corresponding to transmission power. An output of themultiplier 161 is supplied to the quadrature modulator 162 as a signalof an I channel.

The control data supplied to the input terminal 163 is a signal of acontrol-data transmission channel (Dedicated Physical Control Channel:DPCCH) and is multiplied in the multiplier 164 by a gain coefficient βccorresponding to the transmission power to be made into an orthogonal Qchannel in the multiplier 165 and then supplied to the quadraturemodulator 162.

In the quadrature modulator 162, quadrature modulation is performed onthe I-channel signal and Q-channel signal to be a transmission signal(I+j·Q), which is supplied to the modulator 113. In this connection, thegain coefficient βd multiplying in the multiplier 161 is variably setdepending on an amount of transmission data (user data) output from thetransmission buffer 119, so that transmission rate can variably be set.For example, when there is no user data to transmit, the gaincoefficient βd is set to zero and the quadrature modulator 162 mayoutput only a signal of the control-data transmission channel (DPCCH) asthe transmission signal. When there exists the user data to betransmitted, the gain coefficient βd is set to a value in response tothe transmission power at that time. The state in which the gain of userdata is set to zero is one that the transmission power for the mobilephone unit 100 is set to the minimum. When transmission processing isactually performed, a congestion management function (also termed flowcontrol) of performing control to make an amount of data temporarilystored in the transmission buffer 119 fall within a predetermined rangeis executed under the control of CPU 117 or the like. This flow controlwill be described later in detail.

FIG. 3 shows an example of a software-hierarchy model when communicationis made by the mobile phone part 110 of the mobile phone unit 100 inthis embodiment. As is shown, a plurality of layers of software areprepared on a hardware portion 201. Specifically, on the hardwareportion 201 is prepared a physical layer (layer 1) 202 which performsthe read/write processing and the interrupt processing (also termedinterrupt-handler processing) to the hardware portion 201 and providesthe functions to a data-link layer (layer 2) 203. The data-link layer203 performs order and priority management, retransmitting management,and congestion management of transmission data packets and provides thefunctions to a network layer (layer 3) 204. The network layer 204performs communication-call control, unit-move management and radioresource management and provides the functions to an application layer205. The application layer 205 realizes a user interface, telephonefunction or various applications of the mobile phone.

The data-link layer (layer 2) 203 has a transmission data-packetcongestion management function to manage the transmission buffer.Specifically, when a certain amount of unsent packets or more is storedin the transmission buffer as a demand for transmission increases forexample, the data-link layer 203 issues a wait-before-transmit request(X off) to the upper layer. Further, if transmission processing catchesup to make the unsent packets stored in the transmission buffer fallwithin a certain amount, the data-link layer 203 issues await-before-transmit release request (X on) to the upper layer. Theabove-described flow control is performed by means of such processing ofthe data-link layer 203.

Next, the non-contact IC card function part 120 of the mobile phone unit100 shown in FIG. 1 will be described. In the non-contact IC cardfunction part 120, a short range communication loop antenna 121 isconnected to a communicator 122. Hereupon, it is designed that when theshort range communication loop antenna 121 is brought close to anexternal card reader/writer 150 at a distance of, for example, aboutseveral cm to several tens of cm, the antenna 121 receives an electricpower wave supplied from the reader/writer 150 and supplies the receivedsignal of electric power wave to a capacitor (not shown) in thecommunicator 122 to be charged. The charged signal is employed as adriving power source of the communicator 122. Therefore, when thenon-contact IC card function part 120 comes close to the cardreader/writer 150, the communication is started automatically.

Then, receiving processing of extracting in the communicator 122 datasuperimposed on the electric power wave is performed and a transmissionsignal generated in the communicator 122 can be supplied to the shortrange communication loop antenna 121 to be transmitted to thereader/writer 150 by radio transmission. This transmission processing isperformed also using the power source based on the electric power wavesupplied from the reader/writer 150. A controller 123 is connected tothe communicator 122 to perform such processing as: discriminating datatransmitted by radio from the reader/writer 150, processing ofgenerating data transmitted by radio to the reader/writer 150 and thelike.

Although no particular description is given herein on a specific use ofthe non-contact IC card function part 120, at least identification datafor functioning as the non-contact IC card is set in the controller 123and the identification data is transmitted directly or with encryptionto the reader/writer 150. Moreover, the controller 123 stores necessarydata among data sent from the reader/writer 150.

The controller 123 includes an external interface 124 for making datatransfer with another external interface 118 in the controller 115 onthe side of the mobile phone part 110 through the interface 130 forcommunication between mobile phone and IC card. With this structure, amutual data transfer between the non-contact IC card function part 120and mobile phone part 110 can be performed.

Next, referring to flowcharts of FIG. 4 and after, description will begiven to processing when the mobile phone unit 100 in this embodimentcomes close to the card reader/writer 150 to perform communication withthe card reader/writer 150.

First, the processing to start communication by the non-contact IC cardfunction part 120 of mobile phone unit 100 will be described withreference to the flowchart of FIG. 4. When the communicator 122 in thenon-contact IC card function part 120 receives a signal from thereader/writer (step S11), the controller 123 in the non-contact IC cardfunction part 120 transmits an interrupt start request to the controller115 on the side of the mobile phone part 110 through the externalinterface 124 (step S12).

When the interrupt start request arrives at the controller 115 on theside of the mobile phone part 110, an interrupt notice arrives at theCPU 117 (step S13). When the interrupt occurs in the CPU 117, aninterrupt handler is activated to recognize the cause of theinterruption (in this case, the start of IC card communication) (stepS14) and then a forced congestion mode started is set as a parameter forcontrolling the data-link layer (step S15) to end the processing of thenon-contact IC card function part at the start of communication. It isnoted that the forced congestion mode is a mode that is not set onnormal occasions.

Next, the processing to end communication in the non-contact IC cardfunction part 120 will be described with reference to a flowchart ofFIG. 5. When the communication with the reader/writer in thecommunicator 122 of non-contact IC card function part 120 ends (stepS21), the controller 123 in the non-contact IC card function part 120transmits an interrupt end request to the controller 115 on the side ofthe mobile phone part 110 through the external interface 124 (step S22).

When the interrupt end request arrives at the controller 115 on the sideof the mobile phone part 110, an interrupt notice arrives at the CPU 117(step S23). When the interrupt occurs in the CPU 117, the interrupthandler is activated to recognize the cause of the interruption (in thiscase, the end of IC card communication) (step S24) and a forcedcongestion mode ended is set (step S25) to end the processing ofnon-contact IC card function part at the end of communication.

Next, the processing in the data-link layer (layer 2) 203 on the side ofmobile phone part 110 to receive transmission packets into thetransmission buffer 119 will be described with reference to a flowchartof FIG. 6. When it is detected that the data-link layer receives thetransmission packets (packetized transmission data: for example, audiopacket, data packet, etc.) from the upper layer (step S31), whether ornot the forced congestion mode is set in the present mode of operationis judged (step S32). When it is judged that the forced congestion modeis set, the upper layer is requested to wait before transmit (step S33).An example of the case where it is judged that the forced congestionmode is being set in step S32 is the case of step S15 shown in theflowchart of FIG. 4, in which the non-contact IC-card communication isstarted.

When it is judged that the forced congestion mode is not set in stepS32, whether or not an amount of data stored in the transmission bufferexceeds a start threshold to stop transmission is judged (step S34), andif the start threshold to stop transmission is exceeded, the processingmoves to step S33 and the upper layer is also requested to wait beforetransmit. If the start threshold to stop transmission is not exceeded,the received transmission packets are stored in the transmission buffer119 (step S35).

Next, the processing in the data-link layer to transmit data thus storedin the transmission buffer 119 will be described with reference to aflowchart of FIG. 7. Timing to transmit the packets is conventionallyset in regular cycles; and when the time to transmit the packet has come(step S41), whether the present mode of operation is the forcedcongestion mode or not is judged (step S42). If the forced congestionmode has been set in this step, the transmission processing in thedata-link layer is ended and the data-link layer waits for the next timeto transmit the packet.

If it is judged that no forced congestion mode is set in step S42,whether or not there is any data remaining in the transmission buffer isjudged (step S43). When there is no residual data in the transmissionbuffer, the transmission processing also comes to an end and thedata-link layer waits for the next time to transmit the packet.

When it is judged that there is residual data in the transmission bufferin step S43, data stored in the transmission buffer is output therefromand the output data is processed to transmit (step S44). Subsequently,whether the amount of stored data is less than a release threshold tostop transmission in the transmission buffer is judged (step S45), andthe transmission processing is continued in step S44 until to be lessthan the release threshold to stop transmission; and if the amountbecomes less than the release threshold to stop transmission, thedata-link layer 203 notifies the upper layer of the wait-before-transmitrelease request (step S46) and the transmission processing at this timeis ended. Additionally, having described herein the receiving processing(FIG. 6) and transmission processing (FIG. 7) on the transmissionpackets as asynchronous separate processing, those two sets ofprocessing may be performed as a sequence of processing.

As described above, when the transmission processing in the mobile phonepart 110 of mobile phone unit 100 in this embodiment is performed andcommunication in the non-contact IC card function part 120 incorporatedin the unit 100 is started, the forced congestion mode is immediatelyset to stop input processing of transmission data into the transmissionbuffer in mobile phone part 110, whereby transmission of user data fromthe unit 100 to the base station will be stopped. Therefore,communication in the non-contact IC card function part 120 will notinterfere with communication in the mobile phone part 110, so thatradio-wave interference due to simultaneous operation of both thecommunicating parts can be reduced greatly.

When the communication in non-contact IC card function part 120 comes toan end, the forced congestion mode is immediately released to resume theinput processing of transmission data into the transmission buffer inthe mobile phone part 110, whereby the transmission of user data fromthe unit 100 to the base station will be resumed. Conventionally,communication between the non-contact IC function part 120 and the cardreader/writer is completed in considerably short period of time of aboutone second, and when audio packets for example are transmitted, a mutecondition lasts only for a short time during the communication with thereader/writer; and also when data packets are transmitted, only a slightdelay is caused. Thus, there occurs no large hindrance to the radiotelephone communication.

Moreover, since transmission of only the user data such as audio packetsand data packets is stopped during communication in the non-contact ICcard function part 120 and transmission of the control data is continuedas described with reference to FIG. 2, the connected state of radiotelephone line between the base station and unit 100 is maintained, sothat such accidents as line cutoff due to a temporary stop ofcommunication can be prevented. Furthermore, in the state in whichtransmission of user data is stopped, the transmission is performedunder the minimum transmission power, so that transmission is performedat the lowest rate to suppress interference with the communicationbetween the non-contact IC card function part 120 and reader/writer tothe minimum amount.

Accordingly, in this embodiment, processing to temporarily stoptransmission is performed for preventing the interference, using theflow control function of transmission buffer which is originallypossessed by a communication processor for mobile phone in the mobilephone unit, so that no new circuit is required for hardware, and alsothe function of setting the forced congestion mode which is originallypossessed by the layer only need to be somewhat modified for software tocontrol communication, which can be realized without difficulty and cancontribute to lowering cost of the mobile phone unit and miniaturizationthereof.

Moreover, in the above-described embodiment, when communication in thenon-contact IC card function part is started, processing to stoptransmission is performed, and when the communication in the non-contactIC card function part comes to an end, processing to resume transmissionis performed; however, it may be arranged that, by regarding a timerequired for the communication in non-contact IC card function part asan approximately fixed time (for example a time t of about one second),transmission is stopped after the communication in non-contact IC cardfunction part has started until the time t passes. With thatconfiguration, control processing when the communication in non-contactIC card function part comes to an end can be omitted.

Having described the embodiment in which the non-contact IC cardfunction part is incorporated in the mobile phone unit of W-CDMA system,it is needless to say that the present invention is also applicable to acase where the non-contact IC card function part is incorporated in amobile phone unit of other systems.

1. A radio communication method in a phone having a first partoperatively configured to effect a first bidirectional radiocommunication with a predetermined station and a second part operativelyconfigured to effect a second bidirectional radio communication with areader/writer when the phone is positioned adjacent to thereader/writer, the method comprising: detecting, via the second part ofthe phone, a signal transmitted by the reader/writer to start the secondradio communication with the reader/writer; and in response to detectingthe signal transmitted by the reader/writer to start the second radiocommunication with said reader/writer, temporarily stopping output oftransmission data in the first radio communication with saidpredetermined station such that the second radio communication isimmediately inhibited from causing interference in the first radiocommunication, wherein the step of temporarily stopping output oftransmission data comprises stopping, via a controller associated withthe second part of the phone, the inputting of transmission data into abuffer that temporarily stores the transmission data, wherein the firstpart of the phone includes a software-hierarchy communication modelhaving a data-link layer and a another layer, the data-link layer beingoperatively configured to manage transmission data congestion associatedwith the other layer when in a first mode and the step of temporarilystopping output of transmission data further comprises temporarilyforcing the data-link layer into the first mode irregardless of whetherthe other layer is in a data congestion state.
 2. A radio communicationunit comprising: a first radio communication processor operativelyconfigured to generate a first bidirectional radio communication with apredetermined station; a second radio communication processoroperatively configured to generate a second bidirectional radiocommunication with an adjacent reader/writer; and a controlleroperatively configured to detect a signal transmitted by thereader/writer for starting the second radio communication with thereader/writer and to temporarily stop output of transmission data insaid first radio communication processor in response to detecting thesignal such that the second radio communication is immediately inhibitedfrom causing interference in the first radio communication; a bufferused by the first radio communication processor to temporarily store thetransmission data for output, wherein the controller stops the output oftransmission data by temporarily inhibiting the input of thetransmission data into the buffer; a software-hierarchy communicationmodel run by the first radio communication processor, the communicationmodel having a data-link layer and an another layer, the data-link layerbeing operatively configured to manage transmission data congestionassociated with the other layer when in a first mode, wherein the stepof temporarily stopping output of transmission data further comprisestemporarily forcing the data-link layer into the first mode irregardlessof whether the other layer is in a data congestion state.